/**
 * @Aurhor 把手给我
 * @Date 2022/9/3 9:07
 * @Version 1.0
 **/
package com.ft.utils;

import java.security.MessageDigest;

public class MD5Utils {
    /**
     * md5加密
     * @param key 输入的数据
     * @return 加密后的数据
     */
    public static String md5(String key) {
        char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
        try {
            byte[] btInput = key.getBytes();
            // 获得MD5摘要算法的 MessageDigest 对象
            MessageDigest mdInst = MessageDigest.getInstance("MD5");
            // 使用指定的字节更新摘要
            mdInst.update(btInput);
            // 获得密文
            byte[] md = mdInst.digest();
            // 把密文转换成十六进制的字符串形式
            int j = md.length;
            char str[] = new char[j * 2];
            int k = 0;
            for (int i = 0; i < j; i++) {
                byte byte0 = md[i];
                str[k++] = hexDigits[byte0 >>> 4 & 0xf];
                str[k++] = hexDigits[byte0 & 0xf];
            }
            return new String(str);
        } catch (Exception e) {
            return null;
        }
    }

    /**
     * 生成微信支付随机字符串
     * @return 32位随机字符串
     */
    public static String randomStr(){
        String[] strings = {"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F","G","H","I","J","K","L",
        "M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
        String str = "";
        for(int i = 0;i<32; i++){
           int T =  (int)(Math.random() * strings.length);
           str += strings[T];
        }
        return str;
    }
}
